multiple centres in UK, Italy, The Netherlands and Poland. For each country, pub-lished local costs have been applied to the resource use. Results have been strati-fied by glomerular filtration rate (GFR) at one-year post-transplant. RESULTS:Across these countries, the total three-year cost of post-transplant care variesdepending on local treatment practices, from a minimum of €36,000 per patient inPoland to a maximum of €77,000 in the The Netherlands. Consistently across allcountries, the average three-year costs decrease as a result of improved graft func-tioning status (increased GFR) at one year. The average three-year costs for a pa-tient with a GFR�45 at one year are 29% lower than those with �30GFR in the TheNetherlands, 40% lower in Italy, 43% lower in Belgium, 50% lower in the UK, and51% lower in Poland. CONCLUSIONS: This study demonstrates that in five Euro-pean countries, worsening post-transplant renal function contributes to substan-tive increases in resource use, with some variation across regions. Therefore man-agement strategies that promote renal function after transplantation are likely toprovide important resource savings. Additional analyses are ongoing in Spain,Czech Republic, Hungary, Germany and Sweden to further confirm these observa-tions.

PSU16MINIMALLY INVASIVE SURGERY IN TOTAL HIP ARTHROPLASTY: A COST-EFFECTIVENESS ANALYSISNavarro espigares JL1, Hernandez torres E1, Ruiz arranz JL2

1Hospital Universitario Virgen De Las Nieves, Granada, Spain, 2Area Sanitaria Serrania DeRonda, Ronda, SpainOBJECTIVES: The main objective of this study is to evaluate the cost-effectivenessof total hip arthroplasty through anterolateral minimally invasive surgery (MIS)and compare it with the traditional approach. METHODS: A study was conductedto compare traditional and minimally invasive surgical techniques for total hiparthroplasty in a population of 340 patients at two Spanish hospitals (the Virgen delas Nieves University Hospital of Granada and the Serranía de Ronda Hospital)during the year 2007. The design of the study was a prospective stochastic cost-effectiveness analysis, where effectiveness data were collected over a one-yearperiod at individual patient levels and costs were gathered from the analyticalaccounting system of Virgen de las Nieves University Hospital. Effectiveness wasmeasured in functional terms (clinical) and self-perceived quality of life (SF-12survey) during the first 6 postoperative weeks. RESULTS: After 6 postoperativeweeks, in comparison with the conventional technique, a pattern in improvementsfor MIS was observed for length of hospital stay (hospitalization time was 4.97 daysshorter); for operative time (an average of 83.3 minutes for MIS patients and 97.8minutes for the control group); and for average length of skin incision (9.83 cm. forthe MIS group and 16.2 cm. for the control group). The total cost of THA with MISwas lower (4519.19 €) than the cost of traditional hip replacement (6722.46 €). In-cremental effectiveness value in terms of quality of life was 0.11 points in the SF-12survey for MIS. The cost-effectiveness analysis reveals a strong dominance of MISversus traditional THA. CONCLUSIONS: The study showed that the minimally in-vasive technique reduces inpatient resource utilization and improves self per-ceived quality of life of patients compared with the traditional approach. The morebeneficial incremental effectiveness ratio of MIS versus traditional THA supportsthe recommendation for expanded use of minimally invasive surgery.

PSU17COST-EFFECTIVENESS OF DSAEK VERSUS PK FOR CORNEALENDOTHELIALDISEASEPatel S, Kaakeh R, Shtein R, Smith DUniversity of Michigan, Ann Arbor, MI, USAOBJECTIVES: To perform a comparative cost-effectiveness analysis of Descemet’sstripping automated endothelial keratoplasty (DSAEK) and penetrating kerato-plasty (PK) for corneal endothelial disease. METHODS: Systematic review of thepeer-reviewed English literature through a search of PubMed to populate a 5 yearmodel of a) quality adjusted life years (QALYs) associated with clinical outcomes ofthe relatively new DSAEK procedure and the long-established PK procedure, and b)third party payer (US Medicare 2010) costs associated with associated medical,surgical and pharmaceutical services. RESULTS: Five year follow-up focusing onstandard therapy and complications yeilds 2.99 QALYs associated with DSEAK and1.94 QALYs with PK, a difference of 1.05. Following slightly higher sugical costs of$US7925 for DSEAK and $US7544 for PK, total five year costs are $US10,104 associ-ated with DSEAK and $US9840 with PK, a difference of $US264. The ICUR is $US251.Sensitivity analyses of differeing disc dislocation rates, astigmtism complicationrates and cost parameters yield ICURs in the range of $US0 to $US500.CONCLUSIONS: Using the literature on outcomes and costs for treatments of cor-neal endothelial disease, a five year model yields robust results siggesting thatDSEAK is slightly more expensive procedure than PK to third party payers, but withfavorable quality adjusted life year resulting making DSEAK a cost-effective optionunder all scenarios considered.

PSU18COST-UTILITY ANALYSIS OF LAPAROSCOPIC VERSUS OPEN SURGERY FORCOLORECTAL CANCERCallejo D, Guerra M, Reza M, Maeso S, Blasco JAAgencia Laín Entralgo, Madrid, SpainOBJECTIVES: To assess the comparative efficiency of laparoscopic versus opensurgery in colorectal cancer patients. METHODS: To establish relative efficacy oflaparoscopic versus open surgery in all measures that could have clinical or eco-nomic relevance. Using previous systematic reviews and updating their contentswith the new information published after. Meta-analysis technique is used to sum-marize the information. A Markov model is developed to estimate progress in time

of health and resource use obtained with these two alternatives. Measures ofhealth outcomes used in the model were life years and quality adjusted life years.Probabilistic sensitivity analysis was performed to assess uncertainty in the pa-rameters included in the Markov model. RESULTS: Preliminary results show thatcost of laparoscopic-assisted surgery is higher than open surgery in close to 750 €.This difference decreased slightly in the immediate postoperative period due to thelower readmission rate. The difference in costs, coupled with the equivalence inlong-term results obtained by the two techniques makes that any of them can beconsidered efficient for our health system. Since considering a willingness to paybetween 20,000 and 30,000 € per quality-adjusted life year gained, none of thealternatives have above 60% chance to be the best option. CONCLUSIONS: Thelaparoscopic-assisted resection has shown results in terms of overall survival andrecurrence similar to those achieved by open surgery in colorectal surgery patients.The estimated cost for laparoscopic intervention is slightly higher than open sur-gery, but seems to accelerate the postoperative recovery time. This implies thatnone of the two alternatives is clearly superior to the other in terms of efficiency.Therefore, each decision maker at hospital level will assess available human andmaterial resources, and its cost structure to use resources more efficiently.

PSU19THE DOORS-STUDY OF ON-PUMP VERSUS OFF-PUMP CORONARY ARTERYBYPASS GRAFTING: A POST HOC ANALYSIS OF METHODS FOR MULTIPLEIMPUTATION OF MISSING DATA IN ECONOMIC EVALUATIONEhlers L1, Fenger-grøn M2, Beck SS3, Houlind K4, Lauridsen J51Department of Business Studies, Aalborg, Denmark, 2Department of Clinical Epidemiology,Aarhus University Hospital, Denmark & Research Unit for General Practice, Aarhus University,Aarhus, Denmark, 3HTA & Health Services Research, Centre for Public Health, Central DenmarkRegion, Aarhus, Denmark, 4Dept. of Cardiothoracic and Vascular Surgery, Aarhus UniversityHospital, Denmark, Aarhus, Denmark, 5The Research Unit of Health Economics, University ofSouthern Denmark, Denmark, Odense, DenmarkOBJECTIVES: A cost-utility analysis was conducted alongside the Danish On-pumpOff-pump Randomization Study (DOORS) based on the intention to treat principle.METHODS: A post hoc analysis of the problem of missing data was addressed bymultiple imputation using the conditional Gaussian as well as the chained equa-tion approach. Both methods where applied using two different models (represent-ing a data-driven respectively a clinical reasoning selection strategy). RESULTS:The cost-effectiveness acceptability curve for the complete case analysis (n�779)showed 88 % probability of OPCAB being cost-effective at a threshold value of£30.000 per QALY. In analyses based on the conditional Gaussians approach andthe chained equations approach to multiple imputation the results was 73-75 %.CONCLUSIONS: The result of the previously published complete-case analysis ofthe cost-effectiveness of OPCAB versus CCABG was reinforced by this post hocanalysis of the uncertainty due to missing data. The analysis showed that theconditional Gaussian approach and the chained equations approach producedsimilar results Evidence about the long term cost-effectiveness of OPCAB versusCCABG is warranted.

Surgery – Patient-Reported Outcomes & Preference-Based Studies

PSU20ESTIMATING PREFERENCES FOR ECONOMIC EVALUATION IN PATIENTS WITHLOCALIZED PROSTATE CANCERAvila MM1, Becerra V1, Cunillera O1, Pardo Y2, Ferrer M3

1IMIM (Institut de Recerca Hospital del Mar), Barcelona, Catalunya, Spain, 2IMIM (Institut deRecerca Hospital del Mar), Barcelona, Barcelona, Spain, 3IMIM-Hospital del Mar, Barcelona,Barcelona, SpainOBJECTIVES: The high variability on preferences estimates for prostate cancercould be explained by differences in methods, techniques and obtaining popula-tions. Our aim was to estimate the preferences and willingness to pay of patients inthe “Spanish Multicenter Study of Localized Prostate Cancer” at 5 years of follow-up, according to the treatment received (radical prostatectomy, external radiother-apy and brachytherapy). METHODS: Data analyzed were from the 5-year follow-upevaluation of the “Spanish Multicenter Study of Localized Prostate Cancer”, inwhich patients completed the preference questionnaire. The estimation of prefer-ences was conducted using the indirect method (from the SF-6D index), and thedirect method using the Standard Gamble (SG) and Time Trade-Off (TTO) tech-niques. We also assessed the patients’ Willingness-to Pay (WTP). The three treat-ment groups were compared using the Kruskall Wallis test. RESULTS: Of the 441patients enrolled, 105 were treated with radical prostatectomy, 137 with externalradiotherapy and 199 with prostate brachytherapy. Most patients were married orliving with a partner (89.6%), were retired (76%) and had completed primary orsecondary studies (53.5%). Utilities measured with the SF-6D showed no statisti-cally significant differences by treatment group (p � 0.356). The utilities measuredby TTO presented the greatest differences according to treatment: mean of 0.94 inthe radical prostatectomy group, 0.99 in external radiotherapy and 0.98 in brachy-therapy (p �0.001). The willingness to pay also showed significant differences:mean of 58.4 € in the radical prostatectomy group, 32.04 € in external radiotherapyand 28.8 € in brachytherapy (p �0.01). CONCLUSIONS: The estimates of preferencesvary according to the method and the technique used to obtain them. Both theutilities obtained by the direct method and the ones through willingness to payindicate that radical prostatectomy is the worst valued treatment, prostate brachy-therapy being the most valued by patients with localized prostate cancer.

PSU21SPEECH PROBLEM AND HEALTH-RELATED QUALITY OF LIFE IN HEAD ANDNECK CANCER SURVIVORS AFTER FIVE YEARS OF TREATMENTSPayakachat N1, Suen JY2

A263V A L U E I N H E A L T H 1 4 ( 2 0 1 1 ) A 2 3 3 - A 5 1 0

Navarro Espigares, JL2; Hernández Torres, Elisa; Ruiz Arranz, JL

University Hospital Virgen de las Nieves (Granada, Spain). http://www.hvn.es/index.php

MINIMALLY INVASIVE SURGERY IN TOTAL HIP ARTHROPLASTY. A COST-EFFECTIVENESS ANALYSIS1

1 Research project funded by Instituto de Salud Carlos III. PI060668 Project : Análisis coste-efectividad de la artroplastia total de cadera con cirugía

mínimamente invasiva versus abordaje tradicional. 2 Contact information: José Luis Navarro Espigares. Hospital Universitario Virgen de las Nieves.

Avenida Fuerzas Armadas. 18014 Granada – Spain. E: josel.navarro.sspa@juntadeandalucia.es

ISPOR 14TH ANNUAL EUROPEAN CONGRESS. 4-8 NOVEMBER, 2011. MADRID (SPAIN)

Table 1: Clinical Results BACKGROUND In recent years there has been a growing interest in developing minimally

invasive techniques (MIS), which have moved to the hip surgery with the objective of breaking less soft tissue, reduce blood loss, improve aesthetics and speed rehabilitation

The published literature contains objective evidence of the positive impact of MIS on the effectiveness in relation to functional outcomes, hospital stay and surgical aggressiveness of the intervention, with a greater number of effectiveness studies that support MIS than studies on complications and disadvantages of this technique.

OBJECTIVES

The main objective of this work is to determine the cost-effectiveness of total hip arthroplasty by means of minimal invasive surgery (MIS) in comparison with traditional surgical techniques (THA).

METHODS A study was conducted to compare traditional and minimally invasive surgical

techniques for total hip arthroplasty in a population of 340 patients at two Spanish hospitals (the Virgen de las Nieves University Hospital of Granada and the Serranía de Ronda Hospital) during the year 2007.

The design of the study was a prospective stochastic cost-effectiveness analysis, where effectiveness data were collected over a one-year period at individual patient levels and costs were gathered from the analytical accounting system of Virgen de las Nieves University Hospital. Effectiveness was measured in functional terms (clinical) and self-perceived quality of life (SF-12 survey) during the first 6 postoperative weeks.

RESULTS After 6 postoperative weeks, in comparison with the conventional technique, a

pattern in improvements for MIS was observed for length of hospital stay (hospitalization time was 4.42 days shorter); for operative time (an average of 94.80 minutes for MIS patients and 94.64 minutes for the control group); and for average length of skin incision (9.86 cm. for the MIS group and 15.56 cm. for the control group) (Table 1).

Differential effectiveness value in terms of quality of life was -1,73 and 2,52 in physical and mental dimensions of the the SF-12 survey respectively (Table 2).

The total cost of THA with MIS (5,314.94€) was lower than the cost of traditional hip replacement (8,739.20€) (Table 3).

The cost-effectiveness analysis reveals a strong dominance of MIS versus traditional THA (Table 4, Illustration).

CONCLUSIONS The study showed that the minimally invasive technique reduces inpatient

resource utilization and improves self perceived quality of life of patients compared with the traditional approach. The more beneficial incremental effectiveness ratio of MIS versus traditional THA supports the recommendation for expanded use of minimally invasive surgery.

Table 2: Quality of life results (SF-12)

Table 3: Cost per episode

Table 4: Deterministic cost-effectiveness analysis

Illustration: Cost-effectiveness plane

Variable THA MIS Dif. p N 50 50

Length of hospital stay 8.72 4.30 4.42 0,00 Operational Time 94.64 91.80 2.84 0,60 Lenght of incision 15.56 9.86 5.70 0,00

SF12 Dimension Measurement Technique N Average SD Dif. p

PHYSICAL Basal THA 50 29.44 5.06 -2.34 .00 MIS 50 31.78 3.12 Post-interv. THA 46 32.81 6.42 -4.08 .00 MIS 50 36.89 4.95 Difference THA 46 3.38 8.49 -1.73 .20 MIS 50 5.11 6.46

MENTAL Basal THA 50 52.38 5.98 0.41 .67 MIS 50 51.97 5.35 Post-interv. THA 46 49.44 5.61 2.93 .00 MIS 50 46.52 3.78 Difference THA 46 -2.93 7.70 2.52 .04 MIS 50 -5.45 5.43

THA MIS Dif. p† N 50 50

Average 8,739.20 5,314.94 3424.26 0.00 SD 3,226.83 358.63

IC 95% L. Inf 7,822.14 5,213.02 2513.09 L. Sup 9,656.25 5,416.86 4335.44

Min 5,082.52 5,082.52 Max 22,901.08 5,857.24

Variable Δ Effectiveness Δ Cost CEIR

Length of hospital stay 4.42 Sig. 3,424.26 Sig. 774.72

Operative Time 2.84 NS 3,424.26 Sig. 1,205.73

length incision 5.70 Sig. 3,424.26 Sig. 600.75

SF12 Physical -1.73 Sig. 3,424.26 Sig. -1,977.06

Mental 2.52 NS 3,424.26 Sig. 1,359.75

Stay

Surgical Time

length of incision

SF12 Physical

SF12 Mental

-4.000,00

-3.000,00

-2.000,00

-1.000,00

0,00

1.000,00

2.000,00

3.000,00

4.000,00

-4,00 -2,00 0,00 2,00 4,00 6,00 8,00

Var

. Cos

ts

Var. Effectiveness